Methods and Compositions for Treating Melanoma and Non-Melanoma Skin Cancers

ABSTRACT

Compositions comprising select aryl alkanones and the use thereof in the treatment of melanoma and non-melanoma skin cancer.

RELATED APPLICATIONS

The present application is a divisional application of pending U.S.Non-Provisional patent application Ser. No. 18/101,082, filed on Jan.24, 2023, which claims the benefit of U.S. Provisional Application Ser.Nos. 63/306,246 and 63/306,253 filed 3 Feb. 2022 entitled “Methods andCompositions for Treating and Preventing Cancer,” the contents of bothof which are hereby incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present teachings relate to select aryl alkanone compounds andcompositions for use in the treatment of melanoma and non-melanoma skincancers as well as the use thereof in the treatment of melanoma andnon-melanoma skin cancers.

BACKGROUND

According to the World Health Organization (WHO) cancer is a leadingcause of death worldwide. The disease accounted for about 19.3 millionnew cases and 10 million deaths worldwide in 2020. The main types ofcancer leading to overall cancer mortality each year are: lung (1.8million deaths), colorectal (916,000 deaths), liver (830,000 deaths),stomach (769,000 deaths), and female breast cancer (685,000 deaths). Theglobal cancer burden is projected to continue to rise to 28.4 millioncases by the year 2040.

During a cell's normal lifecycle, it encounters numerous challengeswhere it must decide whether to proliferate, differentiate or die. Adefect in any of these processes may result in cancer, or theuncontrolled growth of the cell. Cancer, in general, has traditionallybeen treated with one or more, preferably a combination of, three typesof therapies: surgery, radiation, and chemotherapy. The adverse effectsof systemic chemotherapy are feared the most by patients; these caninclude nausea, vomiting, and a wide range of complications that impacton the patient's quality of life. Pain is a prevalent symptom in cancerpatients, affecting up to 50% of patients undergoing active cancertreatment and up to 90% of those with advanced disease. In addition tothe physical and emotional suffering due to the diagnosis of cancer,patients are subjected to additional discomfort and symptoms associatedwith both the disease and its treatment.

Though not a leading type of cancer skin cancers are among the deadliestwith melanoma being the deadliest form of skin cancer. In 2020 on aworld-wide basis, non-melanoma skin cancer was responsible for over 1.2million new cases (excluding basal cell carcinoma) and 64,000 deathswith melanoma skin cancer adding a further 325,000 new cases and 57,000deaths. Melanoma has a high propensity for hematogenous and lymphaticdissemination to regional and distant sites in the body and is poorlyresponsive to most systemic therapies. The 5-year survival rate formetastatic melanoma is dismal, ranging from 5% to 10% with a mediansurvival of less than 8 months with treatment.

It is well established that many molecules, particularly cellular DNA,in the skin absorb ultraviolet (UV) radiation upon exposure. Inparticular, cellular DNA strongly absorbs shorter wavelength solar UVradiation resulting in various types of DNA damage as well as theproduction of various DNA photoproducts including, predominantly,cyclobutane pyrimidine dimers (CPDs). Although these lesions areefficiently repaired by one's natural processes in the skin, CPD alsoformation results in various acute effects (erythema, inflammatoryresponses), transient effects (suppression of immune function), andchronic effects (mutation induction and skin cancer). Statistics are nowindicating that the rate of increase in both melanoma and non-melanomaskin cancers is beginning to slow down due to the extensive efforts toraise awareness and teach preventative measures such as sun avoidance,application of full-spectrum sunscreens and use of antioxidant creams.Despite these advances, the absolute numbers continue to climb due tothe shortcomings of the current preventative measures. For example,neither sunscreens nor topical antioxidants have been shown toeffectively block the effects of UV radiation. In part, the level ofantioxidants contained in the majority of skin creams is too low orineffective to have a major impact on free radical damage. Similarly,sunscreens absorb only a portion of UV radiation and many fail to bephotostable following a few minutes of sun exposure [H Gonzalez, NTarras-Wahlberg, B Stromdahl, A Juzeniene, J Moan, O Larko, A Rosen, A MWennberg, Photostability of commercial sunscreens upon sun exposure andirradiation by ultraviolet lamps, BMC Dermatology, 7:1 (2007)www.biomedicalcentral.com/1471-594517/1]. Furthermore, observationalstudies have repeatedly found sunscreen use to be associated with higherrisk of cutaneous melanoma and basal cell skin cancer. This correlationis hypothesized to exist because sunscreens delay the appearance ofsunburn, encouraging prolonged sun exposure and thereby increasing skincancer risk [Yasmeen Kabir, Rachel Seidel, Braden Mcknight, Ronald Moy,DNA Repair Enzymes: An Important Role in Skin Cancer Prevention andReversal of Photodamage—A Review of the Literature, J Drugs Dermatol.14(3):297-301, 2015].

Melanoma is a malignant tumor of melanocytes, cells that are derivedfrom the neural crest. Although most melanomas arise in the skin, theymay also arise from mucosal surfaces or develop at other sites to whichneural crest cells migrate. More than half of primary melanomas occur inareas of the skin often exposed to the sun. Early signs suggestingmalignant change include darker or variable discoloration of the skin,itching, an increase in size of colored domains, or the development ofsmall new patches of color (satellites) around a larger lesion.Ulceration and/or bleeding are later signs. Melanoma most often appearson the trunk, head, or neck of affected men. In women, this type ofcancer most often develops on the lower legs. In both men and women,melanoma can occur on skin that hasn't been exposed to the sun. Melanomacan affect people of any skin tone. In people with darker skin tones,melanoma tends to occur on the palms or soles, or under the fingernailsor toenails. Although early-stage disease is curable by surgery, theprognosis associated with metastasis to distant sites is poor; andmedian survival is only 4 to 6 months. With no sensitive tools availableto monitor therapy and follow-up, these statistics reflect theunpredictable pattern of recurrence of melanoma, as well as itsresistance to treatment by radiation and chemotherapy.

Melanoma, when detected at later stages is arguably one of the mostlethal cancers and the cause of more years of lost life than any othercancer among young adults. There is no standard therapy foradvanced-stage melanoma and the median survival time for patients withmetastatic melanoma is <1 yr. With such a dismal prognosis and lack ofsuccessful therapies and the continued growth in the numbers ofindividuals being diagnosed with melanoma, there is a huge unmet need toidentify means to effectively treat melanoma and, most importantly, toretard and/or mitigate its manifestation and proliferation.

Further exacerbating the issue of skin cancer and melanoma is thewell-known fact that chronic exposure to UV and ionizing radiation leadsto DNA damage. This process underlies photoaging, a term that broadlyencompasses changes in the skin associated with life-long exposure tothe sun: wrinkling, skin laxity, erythema, and hyperpigmentation. Moreimportant from a clinical perspective is the well-documented role of DNAdamage as the provoking event in mutagenesis and tumor development. DNAdamage induced by ultraviolet radiation (UVR) is considered to play adirect part in the initiation of skin cancers.

DNA damage arising from UV exposure is arguably one of the most, if notthe most, relevant type of photodamage initiated by sun exposure. Asnoted above, research has identified dipyrimidine lesions, most notablycyclobutane pyrimidine dimers (CPDs) and 6-4 pyrimidine-pyrimidonephotoproducts as the predominant products of such DNA photodamage: CPDconstituting ˜80% of the total lesions. More recent studies have alsoidentified CPDs as the main class of DNA lesions responsible forinduction of melanoma and non-melanoma skin cancers [Douki, T,Sunlight-induced DNA Damage: Molecular Mechanisms and PhotoprotectionStrategies,” Skin Stress Response Pathways (Wondrak, G. T. ed.), pp,49-77, 2016—DOI: 10.1007/978-3-319-43157-4_3; GP Pfeifer and ABesaratinia, UV wavelength-dependent DNA damage and human non-melanomaand melanoma skin cancer, Photochem Photobiol Sci, 11:90-97, 2012].

Previously, Brash et al had shown that Chemiexcitation of melaninderivatives induces DNA photoproducts long after UV exposure [S Premi, SWallisch, C M Mano, A B Weiner, A Bacchiocchi, K Wakamatsu, E J HBechara, R Halaban, T Douki, DE Brash, Chemiexcitation of melaninderivatives induces DNA photoproducts long after UV exposure, Science,347(6224):842-847, 2015]. These authors have further demonstrated thatthe presence of melanin, activation of iNOS and NOX, and the tripletstate were required for dark CPD formation.

More recently, Chaudhuri et. al. affirmed the continued production ofCPDs long after UV exposure ended (these CPDs often referred to asdark-CPDs or dCPDs) and found that acetyl zingerone was efficacious ininhibiting dCPD formation and proposed its use as an additive tosunscreen and daily skin care formulations for that specific purpose.[Chaudhuri, R K et. al., Acetyl Zingerone: An EfficaciousMultifunctional Ingredient for Continued Protection Against Ongoing DNADamage in Melanocytes After Sun Exposure Ends,” International Journal ofCosmetic Science, 2019, 1-10—DOI:10.1111/ics.12582].

Despite these advances in preventative measures and sun protectiveproducts, melanoma and non-melanoma skin cancers continue to proliferateand survival rates continue to be dismal, especially as compared toadvancements being made against other cancers. Indeed, melanomacontinues to be extremely lethal.

In following there continues to be an urgent and huge unmet need todevelop effective methods and compositions that can treat skin cancersas well as methods and compositions that can mitigate and/or delay itsonset and proliferation.

SUMMARY OF THE INVENTION

Surprisingly, it has now been found that certain aryl alkanonesaccording to Structure 1

wherein R₁, R₂, R₃, R₄ and R₅, which may be the same or different, areeach independently H, OH, alkyl or alkoxy, provided that at least one ofR₁, R₂, R₃, R₄ and R₅ is not H, preferably at least one of R₁, R₂, R₃,R₄ and R₅ is OH or OCH₃, and wherein the alkyl or alkoxy groups, ifpresent, are linear or branched and have from 1 to 8 carbon atoms,preferably from 1 to 6 carbon atoms, most preferably from 1 to 4 carbonatoms, are very effective in up-regulating genes that are adverselyaffected by, particularly down regulated by, non-melanoma skin cancersand/or melanoma and in down-regulating genes that are otherwiseup-regulated by non-melanoma skin cancers and melanoma as well as in thetreatment of such cancers. In particular, these compounds have beenfound to be effective for treating melanoma and non-melanoma skincancers, especially in mitigating, interfering with and/or reversing theproliferation, including metastization, of non-melanoma and melanomaskin cancers, particularly in humans. Preferably the compounds ofStructure 1 are those wherein R₁, R₂, R₃, R₄ and R₅ are H, OH or alkoxy.More preferably, the compounds of Structure 1 are those wherein R₁ andR₂ are H and R₃, R₄ and R₅, which may be the same or different, are eachindependently H, OH, or C₁ to C₄ alkoxy, provided that at least one ofR₃, R₄ and R₅ is not H.

In following, in accordance with the present teaching there are providedtopical, oral, intravenous, intraperitoneal, and/or subcutaneousadministrable compositions comprising at least one compound according toStructure 1. Typically, and preferably, these compositions also includea suitable carrier, particularly, depending upon the mode ofadministration, a pharmaceutically acceptable carrier. Preferably, theamount of the compound(s) according to Structure 1 in such compositionsis from 0.05 to 25 percent, preferably from 0.1 to 20 percent, morepreferably from 0.5 to 15 percent by weight based on the total weight ofthe composition. These compositions may further contain otheringredients commonly co-administered with anti-cancer therapeutic,especially immuno- and chemo-therapeutic, active agents and the like, inconventional amounts.

In accordance with another aspect of the present teaching there areprovided topical, oral, intravenous, intraperitoneal and/or subcutaneousadministrable compositions comprising at least one compound according toStructure 1 in combination with at least one other anti-cancertherapeutic, especially immuno- and/or chemo-therapeutic, active agentsfor the treatment of melanoma and/or non-melanoma skin cancer.Typically, and preferably, these compositions also include a suitablecarrier, particularly, depending upon the mode of administration, apharmaceutically acceptable carrier. The other anti-cancer active agentsare those known or believed or suspected to be suitable for use in thetreatment of non-melanoma and/or melanoma skin cancers. Exemplaryanti-cancer active agents include, but are not limited to, dacarbazine;AMPK activator; immune checkpoint inhibitors (ICI); BRAF and MEKinhibitors, including dabrafenib (Tafinlar), trametinib (Mekinist),vemurafenib (Zelboraf), cobimetinib (Cotellic), encorafenib (Braftovi)and binimetinib (Mektovi); PD-1 inhibitors, including pembrolizumab(Keytruda) and nivolumab (Opdivo); CTLA-4 inhibitors, includingipilimumab (Yervoy), and the like, as well as combinations of any two ormore of the foregoing. Indeed, suitable combinations of such anti-canceractive agents are already well known and/or in development. Preferably,the amount of the compound(s) according to Structure 1 in suchcompositions is from 0.05 to 25 percent, preferably from 0.1 to 20percent, more preferably from 0.5 to 15 percent by weight based on thetotal weight of the composition. The other anti-cancer agents arepresent in their conventional therapeutically effective amounts;however, as there appears to be a level of synergy that arises with thecombination of compounds according to Structure 1 and the otheranti-cancer active agents which provides for an enhanced effect inmitigating, interfering with and/or reversing the proliferation ofmelanoma and/or non-melanoma skin cancer which allows for use of alesser amount of the conventional agent to achieve the same effect asattained by the conventional agent on its own. These compositions mayfurther contain other ingredients commonly co-administered withanti-cancer therapeutic active agents in conventional amounts.

In accordance yet another aspect of the present teaching there areprovided methods for the treatment of non-melanoma and/or melanoma skincancers said method comprising administering, topically, orally,intravenously, intraperitoneally and/or subcutaneously, atherapeutically effective amount of a composition comprising at leastone compound according to Structure 1 for interfering with, inhibitingor reversing the proliferation of non-melanoma and/or melanoma skincancer. Typically, and preferably, these compositions also comprise anda suitable carrier, especially a pharmaceutically acceptable carrier,for the method of administration. Additionally, these compositions mayhave the one or more compounds of Structure 1 as the sole anti-canceractive agent or they may further comprise one or more other anti-cancertherapeutic, especially immuno- and/or chemo-therapeutic active agents,known or believed or suspected to be suitable for use in the treatmentof non-melanoma and/or melanoma skin cancers and/or one or more otheringredients commonly co-administered with anti-cancer therapeutic activeagents. Preferably, the amount of the compound(s) according to Structure1 in such compositions is from 0.05 to 25 percent, preferably from 0.1to 20 percent, more preferably from 0.5 to 15 percent by weight based onthe total weight of the composition. The other anti-cancer agents arepresent in their conventional therapeutically effective amounts;however, as there appears to be a level of synergy that arises with thecombination of compounds according to Structure 1 and the otheranti-cancer active agents which provides for an enhanced effect inmitigating, interfering with and/or reversing the proliferation ofmelanoma and/or non-melanoma skin cancer, one may use of a lesser amountof the conventional agent to achieve the same desired effect as just theconventional agent on its own. The other ingredients commonlyco-administered with anti-cancer therapeutic active agents are presentin conventional amounts.

DESCRIPTION OF THE FIGURES

FIG. 1 is a graph plot of the cell viability of darkly pigmented normalmouse melanocytes to increasing concentrations of acetyl zingerone andMBPD.

FIG. 2 is a graph plot of the cell viability of patient derived,NRAS-mutated melanoma cells to increasing concentrations of acetylzingerone and MBPD.

FIG. 3 is a graph plot of the cell viability of in-house developed,Trametinib resistant, NRAS-mutated melanoma cells to increasingconcentrations of trametinib and combinations thereof with MBPD.

DETAILED DESCRIPTION

As used in the present specification, the following terms shall have themeanings as presented:

“Patient” refers to a human individual.

“Pharmaceutically acceptable” means that the subject of this descriptorhas been approved or is otherwise approvable by a regulatory agency of agovernment or governmental or is listed in the U.S. Pharmacopoeia orother generally recognized pharmacopoeia for use on or in humans.

“Pharmaceutically acceptable carrier” refers to a pharmaceuticallyacceptable diluent, a pharmaceutically acceptable adjuvant, apharmaceutically acceptable excipient, a pharmaceutically acceptablevehicle or carrier, or a combination of any of the foregoing with whicha pharmacological active agent, including the compounds provided by thepresent disclosure, can be administered to a patient, which does notdestroy or have a marked adverse effect on the pharmacological activityof the therein contained pharmacological active agent or metabolitethereof and which is preferably non-toxic or of acceptable toxicity whenadministered in doses sufficient to provide a therapeutically effectiveamount of the pharmacological active agent or metabolite thereof.

“Pharmaceutical composition” refers to a composition comprising apharmaceutically acceptable carrier and a pharmacological active agentor metabolite, especially, in the case of pharmaceutical compositionsclaimed by the present application.

“Treating” or “treatment” of any disease refers to reversing,alleviating, arresting, inhibiting, interfering and/or ameliorating theappearance and/or proliferation of a disease or at least one of theclinical symptoms of a disease, inhibiting the progress of a disease orat least one of the clinical symptoms of the disease as well as delayingthe onset of a disease or at least one or more symptoms thereof in apatient who is predisposed to a disease, especially as evidenced bygenetic testing, even though that patient does not yet experience ordisplay symptoms of the disease. In following, treating or treatmentalso refers to inhibiting a disease, either physically, (e.g.,stabilization of a discernible symptom), physiologically, (e.g.,stabilization of a physical parameter), or both, and to inhibiting atleast one physical parameter that may or may not be discernible to thepatient.

“Improve” or “improvement” is used to convey the fact that thepharmacological active agent has manifested or effected changes, mostnotably beneficial changes, in either the characteristics and/or thephysical attributes of the tissue to which it is being provided, appliedor administered, including, e.g., necrosis of skin cancer cells. Theseterms are also used to indicate that the symptoms or physicalcharacteristics associated with the diseased state are diminished,reduced, or eliminated.

“Inhibiting” generally refers to delaying the onset of the symptoms,delaying, or stopping the progression of the disease and/or itsmanifestation symptoms, alleviating the symptoms, or eliminating thedisease, condition, or disorder.

“Optional” or “optionally” means that the subsequently describedsubject, event or circumstance is not required or a necessaryconsequence, and that the description includes instances where the eventoccurs and instances where it does not and/or when the subject ispresent and when it is not present.

“Therapeutically effective amount” refers to the amount of a compound orcomposition that, when administered to a patient for treating a disease,or at least one of the clinical symptoms of a disease, is sufficient toaffect such treatment of the disease or symptom thereof. The“therapeutically effective amount” varies depending, for example, on thecompound or composition, the disease and/or symptoms of the disease, theseverity of the disease and/or symptoms of the disease, the age, weight,and/or health of the patient to be treated, the mode of administration,the presence of synergistic agents, the judgment of the prescribingphysician and the like. An appropriate amount of any given compound orcomposition can be ascertained by those skilled in the art and/or iscapable of determination by routine experimentation.

“Therapeutically effective dose” refers to a dose that provides atherapeutically effective amount of the given agent to provide effectivetreatment of a disease in a patient. A therapeutically effective dosevaries from compound/composition to compound/−composition and/or frompatient to patient and depends upon factors such as the condition of thepatient and the route of delivery as well as those described in thepreceding definition of therapeutically effective amount. Atherapeutically effective dose can be determined in accordance withroutine pharmacological procedures known to those skilled in the art. Atherapeutic effective dose also contemplates the use of an initial orcharging dose followed by sequent doses, daily, weekly or whatever,wherein the quantity of the active agent in the initial dose is greaterthan in the subsequent doses.

Erring on the side of caution and to avoid having overlooked orinadvertently omitted certain descriptive matter, particularlycomplementary and supplementary descriptive matter, Applicant herebystates and affirms that the technical publications as well as the patentand patent application publications mentioned herein are allincorporated herein in their entirety by this reference. Indeed, forexample, while Applicant could present page after page of description ofsuitable pharmaceutically acceptable vehicles, such would not beproductive as the same are well known and well recognized by thoseskilled in the art and those that come into being after the filing ofthis application will readily be appreciated as suitable as well. Thesame holds true for many other potential constituents, both active andnon-active, that are employed in pharmaceutical compositions made inaccordance with the present teachings.

According to the present teaching, it has now been found that certainaryl alkanones according to Structure 1

wherein R₁, R₂, R₃, R₄ and R₅, which may be the same or different, areeach independently H, OH, alkyl or alkoxy; preferably H, OH or alkoxy;provided that at least one of R₁, R₂, R₃, R₄ and R₅ is not H, andwherein the alkyl or alkoxy groups, if present, are linear or branchedand have from 1 to 8 carbon atoms, preferably from 1 to 6 carbon atoms,most preferably from 1 to 4 carbon atoms, are very effective inup-regulating genes that are adversely affected by, particularly downregulated by, non-melanoma skin cancers and/or melanoma and indown-regulating genes that are otherwise up-regulated by non-melanomaskin cancers and melanoma as well as in the treatment of such skincancers. In particular, it has been found that these compounds areeffective in mitigating, interfering with and/or reversing theproliferation, including metastasization, of non-melanoma and melanomaskin cancers, particularly in humans. Preferably, the compounds ofStructure 1 are those wherein R₁ and R₂ are H and R₃, R₄ and R₅, whichmay be the same or different, are each independently H, OH, or C₁ to C₄alkoxy, provided that at least one of R₃, R₄ and R₅ is not H.

In following, in accordance with one aspect of the present teachingthere are provided topical, oral, intravenous, intraperitoneal and/orsubcutaneous administrable compositions comprising at least one compoundaccording to Structure 1. Typically, and preferably, these compositionsfurther comprise a carrier suitable for the given mode ofadministration, preferably a pharmaceutically acceptable carrier.Preferably, the amount of the compound(s) according to Structure 1 insuch compositions is from 0.05 to 25 percent, preferably from 0.1 to 20percent, more preferably from 0.5 to 15 percent by weight based on thetotal weight of the composition. These compositions may further containother ingredients commonly co-administered with anti-cancer therapeutic,especially immuno-, and chemo-therapeutic, active agents in conventionalamounts.

In accordance with a second aspect of the present teaching there areprovided topical, oral, intravenous, intraperitoneal and/or subcutaneousadministrable compositions comprising at least one compound according toStructure 1 in combination with at least one other anti-cancertherapeutic, especially immuno- and/or chemo-therapeutic, active agents.Typically, and preferably, these compositions further comprise asuitable carrier, preferably a pharmaceutically acceptable carrier. Theother anti-cancer active agents are those known or believed or suspectedto be suitable for use in the treatment of non-melanoma and/or melanomaskin cancers. Exemplary anti-cancer active agents include, but are notlimited to, dacarbazine; AMPK activator; immune checkpoint inhibitors(ICI); BRAF and MEK inhibitors, including dabrafenib (Tafinlar),trametinib (Mekinist), vemurafenib (Zelboraf), cobimetinib (Cotellic),encorafenib (Braftovi) and binimetinib (Mektovi); PD-1 inhibitors,including pembrolizumab (Keytruda) and nivolumab (Opdivo); CTLA-4inhibitors, including ipilimumab (Yervoy), and the like, as well ascombinations of any two or more of the foregoing. Indeed, suitablecombinations of such anti-cancer active agents are already well knownand/or in development. Preferably, the amount of the compound(s)according to Structure 1 in such compositions is from 0.05 to 25percent, preferably from 0.1 to 20 percent, more preferably from 0.5 to15 percent by weight based on the total weight of the composition. Theother anti-cancer agents are present in their conventionaltherapeutically effective amounts; however, as there appears to be alevel of synergy that arises with the combination of compounds accordingto Structure 1 and the other anti-cancer active agents which providesfor an enhanced effect in mitigating, interfering with and/or reversingthe proliferation of melanoma and/or non-melanoma skin cancer such thatone is able to use a lesser amount of the conventional agent to achievethe same effect as attained by the conventional anti-cancer active agenton its own. These compositions may further contain other ingredientscommonly co-administered with anti-cancer therapeutic active agents inconventional amounts.

In accordance a third aspect of the present teaching there are providedmethods for the treatment of non-melanoma and/or melanoma skin cancerssaid method comprising administering, topically, orally, intravenously,intraperitoneally and/or subcutaneously, to an individual human atherapeutically effective amount of a composition comprising at leastone compound according to Structure 1 for treating melanoma and/ornon-melanoma skin cancer, especially for interfering with, inhibiting orreversing the proliferation of non-melanoma and/or melanoma skin cancer.Typically, and preferably, the composition also a suitable carrier,preferably a therapeutically acceptable carrier, for the method ofadministration.

In accordance a fourth aspect of the present teaching there are providedmethods for the treatment of non-melanoma and/or melanoma skin cancerssaid method comprising administering, topically, orally, intravenously,intraperitoneally and/or subcutaneously, a therapeutically effectiveamount of a composition comprising at least one compound according toStructure 1 and one or more other anti-cancer therapeutic, especiallyimmuno- and/or chemo-therapeutic active agents, known or believed orsuspected to be suitable for use in the treatment of non-melanoma and/ormelanoma skin cancers for treating, especially interfering with,inhibiting or reversing the proliferation of, non-melanoma and/ormelanoma skin cancer. Typically, and preferably, the composition also asuitable carrier, preferably a therapeutically acceptable carrier, forthe method of administration.

In accordance a fifth aspect of the present teaching there are providedmethods for the treatment of non-melanoma and/or melanoma skin cancerssaid method comprising administering, topically, orally, intravenously,intraperitoneally and/or subcutaneously, a therapeutically effectiveamount of a composition comprising at least one compound according toStructure 1 for treating, especially for interfering with, inhibiting orreversing the proliferation of, non-melanoma and/or melanoma skin cancerwhile also administering a therapeutically effective amount of one ormore other anti-cancer therapeutic, especially immuno- and/orchemo-therapeutic active agents, known or believed or suspected to besuitable for use in the treatment of non-melanoma and/or melanoma skincancers, wherein both agents are administered separately, butconcurrently, or wherein one is administered prior to or subsequent tothe other, but essentially in the same treatment regime. In this regard,such administration of the two anti-melanoma and/or anti-non-melanomaskin cancer active agents may be staggered, alternated, in a series ofone then a series of the other, etc.: the gist of this aspect of theclaimed invention being that the treatment regime includes the separateadministration of both the one or more compounds of Structure 1 and theone or more other anti-cancer therapeutic, especially immuno- and/orchemo-therapeutic active agents. In this method it is often desirable toseparately administer other pharmaceutically active agents commonlyco-administered with anti-cancer therapeutic active agents, including,especially antiemetic agents such as anti-nausea agents, antacid agents,and the like, in conventional amounts.

In each of the foregoing methods, the amount of the compound(s)according to Structure 1 in such compositions is typically from 0.05 to25 percent, preferably from 0.1 to 20 percent, more preferably from 0.5to 15 percent by weight based on the total weight of the composition.Similarly, the amount of the other anti-cancer agents in saidcompositions is generally that amount which is conventional for theiruse. However, lesser amounts of the latter may be used due to a level ofsynergy that arises with the combination of compounds according toStructure 1 and the other anti-cancer active agents. Specifically, thecombination provides for an enhanced effect in mitigating, interferingwith and/or reversing the proliferation of melanoma and/or non-melanomaskin cancer as compared to the other anti-cancer active agent orcombination of such agents in the absence of the compound(s) ofStructure 1. Alternatively, one may use a lesser amount of the otheranti-cancer active agent to achieve the same desired effect. In terms ofa total regimen of administrations, the synergy may also shorten theduration of and/or reduce the number of doses of the compositions duringthe treatment regime. Finally, the compositions provided in theaforementioned methods may further contain or be concurrentlyadministered with other ingredients commonly co-administered withanti-cancer therapeutic active agents in conventional amounts.

As noted, the most critical component of the compositions and methods ofthe present teaching is the compound(s) according to Structure 1

wherein R₁, R₂, R₃, R₄ and R₅, which may be the same or different, areeach independently H, OH, alkyl or alkoxy; preferably H, OH or alkoxy;provided that at least one of R₁, R₂, R₃, R₄ and R₅ is not H, andwherein the alkyl or alkoxy groups, if present, are linear or branchedand have from 1 to 8 carbon atoms, preferably from 1 to 6 carbon atoms,most preferably from 1 to 4 carbon atoms. Preferably the compounds ofStructure 1 are those wherein R₁, R₂, R₃, R₄ and R₅ are H, OH or alkoxy,more preferably, those wherein R₁ and R₂ are H and R₃, R₄ and R₅, whichmay be the same or different, are each independently H, OH, or C₁ to C₄alkoxy, provided that at least one of R₂, R₃, R₄ and R₅ is not H.Especially preferred compounds are those wherein R₁ is H and R₂, R₃, R₄and R₅, which may be the same or different, are each independently H,OH, or OCH₃; provided at least one or two of R₂, R₃, R₄ and R₅ is OH orOCH₃ or one of R₂, R₃, R₄ and R₅ is OH and at least one of the remainingmoieties is OH or OCH₃, preferably OCH₃. More preferably R₁ and R₂ are Hand R₃, R₄ and R₅, which may be the same or different, are eachindependently H, OH, or OCH₃; provided at least one or two of R₃, R₄ andR₅ is OH or OCH₃ or one of R₃, R₄ and R₅ is OH and at least one of theremaining moieties is OH or OCH₃, preferably OCH₃. Exemplary preferredcompounds according to Structure 1 are as follows:

-   -   Compound 1: R₁═R₂=R₅═H; R₃═OH; and R₄═OCH₃;    -   Compound 2: R₁═R₂=R₄═R₅═H; and R₃═OCH₃;    -   Compound 3: R₁═R₂=R₄═R₅═H; and R₃═OH;    -   Compound 4: R₁═R₂=R₃═R₅═H; and R₄═OH;    -   Compound 5: R₁═R₂=R₃═R₅═H; and R₄═OCH₃;    -   Compound 6: R₁═R₂=R₃═R₄═H; and R₅═OH;    -   Compound 7: R₁═R₂=R₃═R₄═H; and R₅═OCH₃; and    -   Compound 8: R₁═R₃=R₅═H; and R₂═R₄═OH;

As noted above, the compositions of the present teaching and the methodsof their use may further include one or more one other anti-cancertherapeutic, especially immuno- and/or chemo-therapeutic, active agents,in a suitable carrier. The other anti-cancer active agents are thoseknown or believed or suspected to be suitable for use in the treatmentof non-melanoma and/or melanoma skin cancers. Exemplary anti-canceractive agents include, but are not limited to, dacarbazine; AMPKactivators, including AICAR(5-aminoimidazole-4-carboxamide-ribonucleoside; immune checkpointinhibitors (ICI); BRAF and MEK inhibitors, including dabrafenib(Tafinlar), trametinib (Mekinist), vemurafenib (Zelboraf), cobimetinib(Cotellic), encorafenib (Braftovi) and binimetinib (Mektovi); PD-1inhibitors, including pembrolizumab (Keytruda) and nivolumab (Opdivo);CTLA-4 inhibitors, including ipilimumab (Yervoy), and the like, as wellas combinations of any two or more of the foregoing. Exemplarycombinations of such anti-cancer active agents include, but are notlimited to, combination regimens of BRAF and MEK inhibitors, acombination of nivolumab (Opdivo) and ipilimumab (Yervoy), dabrafenib(Tafinlar) plus trametinib (Mekinist), vemurafenib (Zelboraf) pluscobimetinib (Cotellic), and encorafenib (Braftovi) plus binimetinib(Mektovi) as well as other combinations of MEK inhibitions with CDK4/6inhibitors, pan-RAF inhibitors, and/or PI3K inhibitors, among others.

These other anti-cancer active agents may be combined with the compoundsof Structure 1 to form a single composition for administration, or theymay be used in combination with compositions containing the compounds ofStructure 1 but administered separately. They are administered inconventional therapeutically effective amounts for the specific agentand method or mode of administration or, as noted above, may be used atlesser amounts due to synergy between these other anti-cancer agents andthe compounds of Structure 1, as discussed elsewhere herein.

Similarly the compositions of the present teaching, whether having thecompounds of Structure 1 as the sole active agent or in combination withother anti-cancer active agents, may further comprise one or more othernon-anti-cancer actives used to address the ill effects/side effects ofthe anti-cancer treatments and the like. Depending upon the natureand/or purpose of these other non-anti-cancer agents, they may becombined in a single composition with the compounds of Structure 1and/or the other anti-cancer active agents. More commonly andpreferably, they are administered separately prior to, concurrent withand/or subsequent to the administration of the anti-cancer agents. Suchother non-anti-cancer agents include antiemetics, especially anti-nauseaagents, anti-seizure agents, antacids, and the like. Thesenon-anti-cancer actives are administered in conventional therapeuticallyeffective amounts for the specific agent and method or mode ofadministration.

As discussed, the foregoing compositions are effective in the treatmentof melanoma and non-melanoma skin cancers. These compositions aretypically formulated in a unit dosage form, i.e., physically discreteunits suitable as a unitary dose for patients undergoing treatment, witheach unit containing a predetermined quantity of the active agents,specifically the compound(s) of Structure 1, alone or in combinationwith other anti-cancer active agents, as discussed above, calculated toproduce an intended therapeutic effect. A unit dosage form can be for asingle daily dose, for administration 2 times per day, or one ofmultiple daily doses, e.g., 3 or more times per day. When multiple dailydoses are used, a unit dosage form can be the same or different for eachdose. One or more dosage forms typically comprise a dose, which can beadministered to a patient at a single point in time or during a timeinterval.

Following on the foregoing, the amount of a compound of Structure 1contained in a dose depends upon, among other factors, the route ofadministration and whether the state or stage of the disease. In anyevent, the administered dose is typically less than a toxic dose: thoughit may have significant adverse health effects, provided that thedesired beneficial effect is also attained. Toxicity of the compositionsdescribed herein can be determined by standard pharmaceutical proceduresin cell cultures or experimental animals, e.g., by determining the LD₅₀(the dose lethal to 50% of the population) or the LD₁₀₀ (the dose lethalto 100% of the population). The dose ratio between toxic and therapeuticeffect is the therapeutic index. In certain embodiments, a compound ormetabolite thereof may exhibit a high therapeutic index. The dataobtained from these cell culture assays, and animal studies can be usedin formulating a dosage range that is not toxic for use in humans. Adose of a compound of Formula (I) is typically set within a range ofcirculating concentrations in the blood serum or lymphatic fluid, thatinclude the effective dose and that exhibits little or no toxicity. Adose can vary within this range depending upon the dosage form employedand the route of administration utilized. In certain embodiments, anescalating dose can be administered.

The pharmaceutical compositions of the present teaching can beformulated for immediate release or for delayed or controlled release.In this latter regard, certain embodiments, e.g., an orally administeredproduct, can be adapted for controlled release. Controlled deliverytechnologies can improve the absorption of a drug in a particularregion, or regions, of the gastrointestinal tract. Controlled drugdelivery systems are designed to deliver a drug in such a way that thedrug level is maintained within a therapeutically effective window andeffective and safe blood levels are maintained for a period if thesystem continues to deliver the drug with a particular release profilein the gastrointestinal tract. Controlled drug delivery typically andpreferably produces substantially constant blood levels of a drug over aperiod as compared to fluctuations observed with immediate releasedosage forms. For some drugs, maintaining a constant blood and tissueconcentration of the drug throughout the course of therapy is the mostdesirable mode of treatment as immediate release of drugs oftentimescauses blood levels to peak above that level required to elicit adesired response. This results in waste of the drug and/or may cause orexacerbate toxic side effects. In contrast, the controlled delivery of adrug can result in optimum therapy; not only reducing the frequency ofdosing, but also reducing the severity of side effects. Examples ofcontrolled release dosage forms include dissolution-controlled systems,diffusion controlled systems, ion exchange resins, osmoticallycontrolled systems, erodable matrix systems, pH independentformulations, and gastric retention systems.

Though the mode of administration has been characterized above as beingtopical, oral, intravenous, intraperitoneal, and/or subcutaneousadministrable (which essentially covers all routes of administration),it is to be appreciated that this characterization is not intended to belimiting. Indeed, the compositions of the present teaching can beadministered through any conventional method. The specific mode ofapplication or administration is, in part, dependent upon the form ofthe pharmaceutical composition, the primary purpose or target of itsapplication (e.g., the application may be oral if intending to addressthe disease generally or topically if intending to address primarily atopical symptom or location of the disease. Specific suitable modes ofadministration include, for example, intradermal, intramuscular,intraperitoneal, intravenous, subcutaneous, intranasal, epidural, oral,sublingual, intracerebral, intravaginal, transdermal, rectal, orinhalation. Especially preferred modes of administration are oral,topical, intravenous, or intraperitoneal. Indeed, depending upon thestage of the melanoma or non-melanoma skin cancer the best mode ofadministration may be local to the site of the cancer or systemic,especially if the cancer has spread. Finally, the form of thepharmaceutical composition and its delivery system varies depending uponthe parameters already noted. For example, orally administeredpharmaceutical compositions of the present teaching can be inencapsulated form, e.g., encapsulated in liposomes, or asmicroparticles, microcapsules, capsules, etc. Of course, suchencapsulation may be necessary if the compounds of Structure 1 or, ifpresent the other anti-cancer actives are subject to adverse action,degradation, metabolism by the fluids and physiological processes of thestomach and/or intestines. Indeed, such problems may dictate the use ofalternate modes of administration.

As also noted above, the concentration of the compounds of Structure 1in the pharmaceutical composition is from 0.05 to 25 percent, preferablyfrom 0.1 to 20 percent, more preferably from 0.5 to 15 percent by weightbased on the total weight of the composition; however, even these rangesmay vary, and certainly the specific concentration varies within theseranges as the dose or rate of application of the compounds to thepatient will also affect the concentration. Obviously, dosing itselfdepends upon several factors including the concentration and/or purityof the compounds of Structure 1, the efficacy thereof, the individual towhom the pharmaceutical is to be administered, the mode ofadministration, the form in which the pharmaceutical composition is tobe administered, the severity or extent and/or spread of the disease,etc.

The foregoing factors as well as the application thereof in formulatingthe compositions of the present teaching are all as well known in theart whereby the final or actual concentration in the pharmaceuticalcomposition and/or the dose can readily be determined based up simpledose-response testing and the like. For example, an appropriate oraldosage for a particular pharmaceutical composition containing one ormore compounds of Structure 1 will depend, at least in part, on thegastrointestinal absorption properties of the compound, the stability ofthe compound in the gastrointestinal tract, the pharmacokinetics of thecompound and the intended therapeutic profile.

Following on the foregoing, an appropriate controlled release oraldosage and ultimate form of a pharmaceutical composition containing aparticular compound of Structure 1 will also depend upon a number offactors. For example, gastric retention oral dosage forms may beappropriate for compounds absorbed primarily from the uppergastrointestinal tract, and sustained release oral dosage forms may beappropriate for compounds absorbed primarily from the lowergastrointestinal tract. Again, it is to be expected that certaincompounds are absorbed primarily from the small intestine whereas othersare absorbed primarily through the large intestine. It is also to beappreciated that while it is generally accepted that compounds traversethe length of the small intestine in about 3 to 5 hours, there arecompounds that are not easily absorbed by the small intestine or that donot dissolve readily. Thus, in these instances, the window for activeagent absorption in the small intestine may be too short to provide adesired therapeutic effect in which case large intestinal absorptionmust be channeled and/or alternate routes of administration pursued.

Generally speaking, an appropriate dose of a compound of Structure 1, orpharmaceutical composition comprising a compound of Structure 1, can bedetermined according to any one of several well-established protocolsincluding in-vitro and/or in-vivo assays and/or model studies as well asclinical trials. For example, animal studies involving mice, rats, dogs,and/or monkeys can be used to determine an appropriate dose of apharmaceutical compound. Results from animal studies are typicallyextrapolated to determine appropriate doses for use in other species,such as for example, humans.

EXPERIMENTAL Example 1—Cell Viability in Normal Melanocytes v. MelanomaCells

In support of the present teachings several experiments were conductedto assess the cytotoxicity of compound 1 (Acetyl Zingerone (“AZ”),available as Synoxyl® AZ from Sytheon Ltd.) and Compound 4, itsmono-methoxy analog (3-(4-Methoxy-benzyl)-pentane-2,4-dione (MBPD)),towards normal melanocytes (Normal, C57BL/6 mouse melanocytes, darklypigmented), and patient derived, NRAS-mutated melanoma cells. On Day 1,the melanoma cells and normal melanocytes were seeded into the blackwalled 96 well plates (cat. no. -165305, thermo), ˜1000 cells per welland allowed to stand for one day. The normal melanocytes were culturedin OptiMem base medium (Cat. 31985-070, Life Technologies, Carlsbad, CA)supplemented with 7% horse serum (Cat. 100-508, Gemini Bio-Products, W.Sacramento, CA), and 10 ng/ml (16.2 nM) TPA(12-O-tetradecanoylphorbol-13-acetate, Cat. P1585, Sigma, St. Louis, MO)and the melanoma cells were cultured in OptiMem supplemented with 5%horse serum (Cat. 100-500, Gemini Bio-Products, W. Sacramento, CA), noTPA. On Day 2, the cell plates were treated with variousamounts/concentrations of AZ and MBPD (0, 2, 6, 18, 54, 162, 486, 1458μg/ml), which was added directly into the cell culture medium. On Day 5,Alamar blue (cat. no. A50101, Invitrogen) was added in each well andincubated for 1 hr in CO₂ incubator to differentiate between the liveand dead cells: Alamar blue stains only the live cells. Thereafter, thedye was replaced with 100 ul PBS (Cat. no. 14190-144, Gibco) and cellviability as evidenced by fluorescence was recorded (by Bioteksynergy/H1 microplate reader) at 560/590 nm. Cell survival wascalculated by subtracting the background (media only) and thennormalizing those results with the results obtained from the cells thatwere not treated with AZ or MBPD.

The results of this first series of experiments are presented in graphicform in FIGS. 1 (4 biological repeats) and 2 (3 biological repeats) forthe normal melanocytes and melanoma cells, respectively. In thesefigures, the X-axis shows the amounts used in μg/ml, Molar (M) IC₅₀values were calculated using formula weight of each of the compoundsindividually. The results shown in FIG. 1 demonstrate that neither AZnor MBPD were cytotoxic until extremely high levels were present. Basedthis data, IC₅₀ values of these analogs were calculated to be AZ=10.7 Mand MBPD=14.4 M in normal, pigmented melanocytes. In sharp contrast, asshown in FIG. 2 , both AZ and MBPD demonstrated a marked toxicity to themelanoma cells. As indicated, here these same analogs killed theNRAS-mutated, patient derived melanoma cells at significantly lowconcentrations with IC₅₀ values at 1.3 mM for AZ and 0.4 mM for MBPD.These results demonstrate the marked ability and specificity of thecompounds according to Structure 1 as efficacious anti-cancer treatmentsfor use in the treatment of melanoma and non-melanoma skin cancers,without concern as to cytotoxicity of other cells, particularlykeratinocytes.

Example 2—MBPD/Trametinib Synergy

Another series of experiments were conducted similar to those of Example1 in an effort to assess synergies between the compounds of Structure 1and known melanoma treatments. Here, the compounds of Structure 1 werefurther challenged by isolating melanoma cells that were essentiallyresistant to the known agent and assessing the supplementary orsynergistic behavior of the compounds of Structure 1. Specifically,Trametinib resistant human, NRAS mutated, WM1366 melanoma cells werecreated in-house by sequentially treating the cells with variousconcentrations (2 nM-10 nM) of Trametinib for several weeks. Those cellswhich survived 2 nM Trametinib after two weeks, were then incubated with4 nM Trametinib and those that survived 4 nM Trametinib for two weekswere isolated and then incubated with 10 nM for several weeks. This ledto development of resistance in the WM1366 cells. We used these“in-house generated, Trametinib resistant, NRAS-mutated melanoma cells(Trametinib IC₄₀=˜10-20 nM).

In this study, the Trametinib resistant cells were seeded into blackwalled 96 well plates (cat. no. -165305, thermo), ˜1000 cells per wellemploying the same media as noted in Example 1. On Day 2, the cells weretreated with 125 or 62.5 μg/ml MBPD and incubated for 48 hours. After 48hours, fresh cell-culture medium was added with MBPD and Trametinib atconcentrations of 30, 15, 7.5, 3.75, 1.875, and 0.9375 nM and the cellsallowed to sit for 72 hours. On Day 7, Alamar blue (cat. no. A50101,Invitrogen) was added to each well and the cultures incubated for 1 hrin a CO₂ incubator. Thereafter, the dye was replaced with 100 ul PBS(Cat. no. 14190-144, Gibco) and cell viability as evidenced byfluorescence was recorded (by Biotek synergy/H1 microplate reader) at560/590 nm. Cell survival was calculated by subtracting the background(media only) and then normalizing those results with the resultsobtained from the cells that were not treated with MBPD.

The results of this series of experiments are presented in graphic formin FIG. 3 : the data points representing 2 biological repeats. As in theprior figures, the X-axis shows the amounts used in μg/ml, Molar (M)IC₅₀ values were calculated using formula weight of each of thecompounds individually. The results shown in FIG. 3 demonstrate themarked synergy of MBPD, at both low and higher levels, with Trametinibin killing melanoma cells. As calculated, MBPD reduced the TrametinibIC₅₀ by ˜5 fold: clearly a marked, synergistic improvement in efficacy:this in cells that were already pre-conditioned to be resistant orresistive to Trametinib.

Example 3—AMPK Activation

AMPK activation is a known and efficacious treatment for melanoma andnon-melanoma skin cancer (See. e.g., Chen, L. et. al., “AMPK Activationby GSK621 Inhibits Human Melanoma Cells In Vitro and In Vivo”,Biochemical and Biophysical Research Communications 480 (2016),515-521). To ascertain the ability and efficacy of the compounds ofStructure 1 to activate AMPK, a cell assay study was undertaken. In thestudy, human epidermal keratinocytes were grown using EpiLife Media (60μM calcium) supplemented with 0.2% v/v bovine pituitary extract, 1 μg/mlrecombinant human insulin-like growth factor-I, 0.18 μg/mlhydrocortisone, 5 μg/ml bovine transferrin, 0.2 ng/ml human epidermalgrowth factor. The cells were grown at 37±2° C. and 5±1% CO₂. Thekeratinocytes were seeded into 96-well plates and cultured overnight toallow the cells to adhere to the well plates. Prior to experimental use,the growth media was replaced with basal media (unsupplemented EpiLifeMedia) for five hours prior to starting any treatments. The testmaterials and the positive control (resveratrol) were prepared as stocksolutions in DMSO: all treatments in the study, including the non-H₂O₂exposed and untreated group, had a final concentration of 0.5% DMSO.

The ability of the test material to activate AMPK was determined bymeasuring the phosphorylation of AMPK. The epidermal keratinocytes weretreated with the test material prepared in basal media for two hours. Atthe end of the two-hour incubation the culture media was removed and thecells were fixed in 4% formaldehyde for 20 minutes at room temperature.After the fixation, the cells were washed three times with wash solution(1 minute per wash) and any endogenous peroxidase activity was quenchedby adding 100 ul of a 0.3% H₂O₂ solution to the wells and incubating theplate for another 20 minutes. After washing as described above,non-specific antibody binding was blocked by adding 200 ul of blockingbuffer to each well and incubating the plate for 1 hour at roomtemperature. After blocking, 100 ul of an antibody solution whichrecognizes AMPK phosphorylated at Thr-172 was added to each well and theplate was incubated overnight at 4° C. and then washed as describedabove. After this wash, 100 ul of a secondary antibody solution wasadded to the wells and the plate was incubated for 90 minutes at roomtemperature. After washing again as described above, 50 ul of afluorescent substrate solution was added to each well and the plate wasincubated for 30 minutes at room temperature in the dark. After thisincubation, 50 ul of a protein reactive fluorescent stain was added tothe well plate and the plate was incubated for an additional 5 minutesat room temperature in the dark. After this incubation the well platewas read using a fluorometer at 530 ex/590 em to determine AMPKphosphorylation and at 360 ex/485 em to determine total cellularprotein.

The results are presented in Table 1. As noted, even low levels of AZwere found to activate AMPK; however, a modestly higher level, 50 μg/mlprovided a marked effect on AMPK activation, increasing AMPK activity by88.3%. Based on the known anti-melanoma effect of AMPK activation, it isclear that AZ presents itself as an efficacious anti-melanoma treatment.

TABLE 1 AMPK Activation Study Treatment AMPK-P/Protein Ratio Cellsnon-H₂O₂ treated 3.44 ± 0.38 Cells treated with H₂O₂ 3.35 ± 0.50 SynoxylAZ 50 μg/ml 6.48 ± 1.10 Synoxyl AZ 25 μg/ml 4.16 ± 0.65

The foregoing effect of AZ as an AMPK activator and, in turn,anti-melanoma treatment is especially surprising in light of thepro-viability effect of AZ in normal cells, even those in senescence.Specifically, following on the foregoing experimental methodology,additional studies were conducted on the human keratinocytes cells toassess AZ's impact on cell viability as evidenced by an MTT assay aswell as an assessment of its impact on SA-B-Gal activity. In thesestudies, the human epidermal keratinocytes were treated in basal mediafor two hours with the test material and then treated with either 50 uMor 100 uM H₂O₂ in basal media for an additional two hours: the lattertreatment to induce senescence. Following the H₂O₂ treatment, the cellswere placed in with fully supplemented EpiLife media for either 16 hoursafter which changes in cell viability was evaluated via an MTT assay orfor 3 days after which changes in the cellular senescence marker betagalactosidase (SA-B-GAL) was evaluated.

MTT Calculation: the mean MTT absorbance value for untreated cells notexposed to H₂O₂ was calculated and used to represent 100% cellviability. The individual MTT values from the cells undergoing thevarious treatments was then divided by the mean value for the untreatedcells not exposed to H₂O₂ and expressed as a percent to determine thechange in cell viability caused by each treatment.

SA-B-GAL Calculation: To determine the changes in SA-B-GAL expression adirect measure of SA-B-GAL activity was used. At the end of thethree-day incubation the media was removed, 100 ul of ice-cold celllysis buffer was added and the cells were lysed for 5 minutes at 4° C.At the end of this lysis procedure a portion of the lysate was used fora protein assay while 50 ul of the cell lysate was transferred to a newwell plate and combined with an equal volume of SA-B-GAL reaction buffercontaining a fluorescent substrate. This well plate was then incubatedfor 3 hours at 37° C., after which a 50 ul sample of the reaction wascombined with 200 ul of stop solution in a new well plate and the platewas read using a fluorometer (360 ex/485 em). The fluorescence intensitywas then normalized to cellular protein and this ratio was used as anindex of SA-B-GAL activity.

The results of the MTT assay and SA-B-GAL activity studies are presentedin Tables 2 and 3, respectively.

TABLE 2 MTT Assay (Cell Viability) Viability (% of non- H2O2 exposedcells) Treatment 100 μM H₂O₂ 50 μM H₂O₂ Cells non-H₂O₂ treated  100 ±6.2 100.0 ± 3.2  Cells treated with H₂O₂ 74.9 ± 3.6 82.4 ± 7.7 SynoxylAZ 50 μg/ml 100.2 ± 6.5  100.7 ± 8.3⁺  Synoxyl AZ 25 μg/ml 77.4 ± 9.676.1 ± 6.9 Synoxyl AZ 12.5 μg/ml 79.1 ± 1.4  79.9 ± 11.5

TABLE 3 Senescent Associated β-Galactosidase (SA-B-Gal) Activity AssaySA-B-Gal Activity/Protein Treatment 100 μM H₂O₂ 50 μM H₂O₂ Cellsnon-H₂O₂ treated 0.65 ± 0.05 0.60 ± 0.11 Cells treated with H₂O₂  3.67 ±0.36*  3.4 ± 0.52* Synoxyl AZ 50 μg/ml  0.90 ± 0.15*  0.91 ± 0.06*Synoxyl AZ 25 μg/ml 3.95 ± 0.36 3.30 ± 0.23 Synoxyl AZ 12.5 μg/ml 3.29 ±0.37 3.45 ± 0.29

The results shown in Tables 2 and 3 demonstrate the pro-cell viabilitycharacteristic of AZ in normal cells: a result opposite to that seenwith melanoma cells. Equally important is that these showings furthersupport the non-toxicity of AZ to normal cells whereby its use inmelanoma and non-melanoma skin cancer treatment will not adverselyaffect other cells as also supported by Example 1 above.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever.

We claim:
 1. A composition comprising (a) at least one compoundaccording to Structure 1

wherein R₁, R₂, R₃, R₄ and R₅, which may be the same or different, areeach independently H, OH, alkyl or alkoxy, provided that at least one ofR₁, R₂, R₃, R₄ and R₅ is not H, and wherein the alkyl or alkoxy groups,if present, are linear or branched and have from 1 to 8 carbon atoms and(b) a pharmaceutically acceptable carrier wherein pharmaceuticallyacceptable carrier is suitable for the oral, intravenous,intraperitoneal, and/or subcutaneous administration of a pharmaceuticalactive agent.
 2. The composition of claim 1 wherein the pharmaceuticallyacceptable carrier is not one used for application of topicalpharmaceuticals.
 3. The composition of claim 1 wherein R₁ and R₂ are Hand R₃, R₄ and R₅, which may be the same or different, are eachindependently H, OH, or C₁ to C₄ alkoxy, provided that at least one ofR₃, R₄ and R₅ is not H.
 4. The composition of claim 1 wherein R₁ and R₂are H and R₃, R₄ and R₅, which may be the same or different, are eachindependently H, OH, or OCH₃; provided at least one or two of R₃, R₄ andR₅ is OH or OCH₃ or one of R₃, R₄ and R₅ is OH and at least one of theremaining moieties is OH or OCH₃.
 5. The composition of claim 1 whereinthe at least one compound according to Structure 1 is selected from thegroup consisting of: Compound 1 wherein R₁═R₂=R₅═H; R₃═OH; and R₄═OCH₃;Compound 2 wherein R₁═R₂=R₄═R₅═H; and R₃═OCH₃; Compound 3 whereinR₁═R₂=R₄═R₅═H; and R₃═OH; Compound 4 wherein R₁═R₂=R₃═R₅═H; and R₄═OH;Compound 5 wherein R₁═R₂=R₃═R₅═H; and R₄═OCH₃; Compound 6 whereinR₁═R₂=R₃═R₄═H; and R₅═OH; Compound 7 wherein R₁═R₂=R₃═R₄═H; and R₅═OCH₃;and Compound 8 wherein R₁═R₃=R₅═H; and R₂═R₄═OH.
 6. The composition ofclaim 1 wherein the compound according to Structure 1 is present in aneffective amount for treating melanoma and/or non-melanoma skin cancer.7. A composition comprising (a) at least one compound according toStructure 1

wherein R₁, R₂, R₃, R₄ and R₅, which may be the same or different, areeach independently H, OH, alkyl or alkoxy, provided that at least one ofR₁, R₂, R₃, R₄ and R₅ is not H, and wherein the alkyl or alkoxy groups,if present, are linear or branched and have from 1 to 8 carbon atoms and(b) at least one anti-cancer therapeutic active agent.
 8. Thecomposition of claim 7 wherein R₁ and R₂ are H and R₃, R₄ and R₅, whichmay be the same or different, are each independently H, OH, or C₁ to C₄alkoxy, provided that at least one of R₃, R₄ and R₅ is not H.
 9. Thecomposition of claim 7 wherein R₁ and R₂ are H and R₃, R₄ and R₅, whichmay be the same or different, are each independently H, OH, or OCH₃;provided at least one or two of R₃, R₄ and R₅ is OH or OCH₃ or one ofR₃, R₄ and R₅ is OH and at least one of the remaining moieties is OH orOCH₃.
 10. The composition of claim 7 wherein the at least one compoundaccording to Structure 1 is selected from the group consisting of:Compound 1 wherein R₁═R₂=R₅═H; R₃═OH; and R₄═OCH₃; Compound 2 whereinR₁═R₂=R₄═R₅═H; and R₃═OCH₃; Compound 3 wherein R₁═R₂=R₄═R₅═H; and R₃═OH;Compound 4 wherein R₁═R₂=R₃═R₅═H; and R₄═OH; Compound 5 whereinR₁═R₂=R₃═R₅═H; and R₄═OCH₃; Compound 6 wherein R₁═R₂=R₃═R₄═H; and R₅═OH;Compound 7 wherein R₁═R₂=R₃═R₄═H; and R₅═OCH₃; and Compound 8 whereinR₁═R₃=R₅═H; and R₂═R₄═OH.
 11. The composition of claim 7 wherein thecompound according to Structure 1 is present in an effective amount fortreating melanoma and/or non-melanoma skin cancer.
 12. The compositionof claim 7 wherein the at least one anti-cancer therapeutic active agentis a compound or composition know or believed to be effective intreating melanoma and/or non-melanoma skin cancer.
 13. The compositionof claim 12 wherein the at least one anti-cancer therapeutic activeagent is selected from the group consisting of dacarbazine, an AMPKactivator; an immune checkpoint inhibitor (ICI); a BRAF and/or MEKinhibitors, dabrafenib (Tafinlar), trametinib (Mekinist), vemurafenib(Zelboraf), cobimetinib (Cotellic), encorafenib (Braftovi), binimetinib(Mektovi), a PD-1 inhibitor, pembrolizumab (Keytruda), nivolumab(Opdivo), a CTLA-4 inhibitor, ipilimumab (Yervoy), and combinations ofany two or more of the foregoing.
 14. The composition of claim 7 furthercomprising a pharmaceutically acceptable carrier.